时间：2021-04-19 08:06:58 | 栏目：Python代码 | 点击：次
实例如下所示：
>>> import pandas as pd
>>> import numpy as np
>>> ts1 = [0, 1, np.nan, np.nan, np.nan, np.nan]
>>> ts2 = [0, 2, np.nan, 3, np.nan, np.nan]
>>> d = {'X': ts1, 'Y': ts2, 'Z': ts2}
>>> df = pd.DataFrame(data=d)
>>> df
X Y Z
0 0.0 0.0 0.0
1 1.0 2.0 2.0
2 NaN NaN NaN
3 NaN 3.0 3.0
4 NaN NaN NaN
5 NaN NaN NaN
>>> col =['X','Y']
>>> df[col] = df[col].ffill()
>>> df
X Y Z
0 0.0 0.0 0.0
1 1.0 2.0 2.0
2 1.0 2.0 NaN
3 1.0 3.0 3.0
4 1.0 3.0 NaN
5 1.0 3.0 NaN
>>>